He pulled the camouflaged, armoured tank in the Arnold Sports Festival World of Tanks PC Tank Pull event in Melbourne on Saturday.
But better yet, the 27-year-old youth support worker pulled the tank the required 10 metres in 36.65 seconds, which is expected to break the Guinness World Record - with the record being verified.
The burly strongman, from NSW's Central Coast, won the event in front of 'The Terminator' star Arnold Schwarzenegger.
"I really wanted it. Now I can say that I have won the first-ever tank pull event in the world," the 185kg, 195cm man mountain said.
Williams told AAP ahead of the event he'd done a 10-tonne truck before but as it was
on wheels once you started it just rolled with you. "The tank's a whole different ball game. It's almost like you have to be pulling with max effort the entire time," the father-of-two said.
The World of Tanks PC Tank Pull was the fourth of six events in the professional strongman competition.
American Trey Mitchell came second in the event pulling the war vehicle in 46.16 seconds.
